1. Field of the Invention
This invention relates in general to the field of automatic screw feeding machines and in particular to the field of track feeding arrangements, whereby the fasteners are delivered to a driver head of an automatic screw feeding machine and even more particularly to a gravity fed track arrangement for an automatic screw machine.
2. Description of the Prior Art
An automatic screw feeding machine is the terminology which is commonly applied to a machine which arranges fasteners, such as screws, from a bulk, loose form into an arrangement whereby the fasteners are aligned and then individually delivered to a driver head. The driver head is then utilized to drive a single fastener within a pre-existing hole so as to fasten one component to another. The purpose of such machines is, of course, to speed up production by providing rapid fastening of two or more components. Since speed of production is the main objective of such machines, any portion of the machine which tends to jam or malfunction in any manner results in a work stoppage which is contrary to such main objective. Each operation performed upon a fastener which is being utilized within the machine from its bulk supply disposition to its fastened disposition and any point therebetween must necessarily occur in a serial mode whereby one step follows the other. Any one step, therefore, if it is not accomplished properly, will cause a complete shutdown of the machine and production. In today's modern factories, any production shutdown due to a malfunctioning machine must be avoided at all reasonable costs.
Screws or other similar fasteners used in industry are mass produced. Mass production generally involves greater tolerances for a given characteristic such as fastener head height, head diameter, or shank diameter, than corresponding individualized custom machining of screws. Automatic screw feeding machines must accommodate such mass-produced fasteners. The greater tolerances of mass-produced fasteners thereby impose relatively difficult, individualized tasks on automatic screw feeding machines.
One area where an automatic screw feeding machine of the prior art experiences difficulty is in arranging the screws or other fasteners from a bulk disposition to the point where a single fastener is fed to escapement apparatus which then feeds the single fastener to a driver head of the machine. It is generally known in the prior art machines for a rotating drum to contain a large number of fasteners which in accordance with the rotation of the drum are placed onto a track mechanism. The track mechanism orients and aligns each of the fasteners into a single row and through the use of gravity moves the fasteners down the track whereupon the lead fastener is then delivered to pneumatic apparatus. The pneumatic apparatus feeds each of the screws or fasteners, when demanded, to the driver head of the automatic screw feeding machine.
The relative complex and awkward geometry of the various types of screw fasteners does not generally lend the fasteners to a desired alignment and orientation on the track mechanism. The necessity for the track arrangement to feed the screws to the pneumatic apparatus, as stated previously, involves motion of the screws along the track arrangement. The motion of the screws further complicates an already difficult task. The shanks of the screws fit between an opening in the track mechanism while the underpart of the heads of the fasteners rests on the top surfaces of the tracks. The heads of the fasteners butt up against one another while the screw shanks are spaced apart from each other. The space between adjacent screw shanks in combination with the travel motion of the fasteners and the friction between the underside of the head of the fasteners and the top surface of the tracks tend to cause the fasteners to rock or pivot about their heads during the travel down the track arrangement. The rocking results in misalignment and on occasion interference between the heads of adjacent fasteners, which further results in increased friction and resistance to travel down the tracks. Invariably, one or more of the fasteners then become further misoriented or misaligned within the track mechanism. The friction and interference becomes greater, causing further misalignment and ultimately, jamming of the screws within the track mechanism. The end result is production must be shutdown until the jamming is eliminated. The frequency of jamming and the accompanying production stoppage in the prior art, due to the prior art machines, is a very significant problem.
Accordingly, a new, different, and improved gravity track feeding arrangement is desired which decreases the tendency for mass produced fasteners to become misoriented and thereby jam while being fed to additional apparatus which further feeds the fasteners to the driver head of an automatic screw feeding machine. It is also desirous to provide an improved arrangement for loading the fasteners onto the track mechanism with a view toward minimizing the possibility of jamming of the screw feed mechanism.
It is to be noted and especially recognized that there are other objects of the present invention which, although not specifically stated but which objects will be obvious to those skilled in the art to which this invention pertains, are intended to be included within the scope of the present invention.